Spinning or twisting ring, and associated traveler and traveler system

Abstract

The invention relates to a spinning ring (8) for a ring-spinning or ring-twisting machine, having a connecting piece (15) and a ring top (14), the ring top (14) consisting to at least some degree of a sintered tungsten material containing at least 90% tungsten. The invention also relates to a traveler system having a traveler made of HS steel.

Description

[0001] The invention relates to a ring for a ring spinning or ring twisting machine and a ring-runner system. Rings are used as spinning rings in so-called ring spinning machines or as twisting rings in so-called twisting machines. Hereinafter, spinning rings and twisting rings are collectively referred to as spinning rings. The spinning rings interact with mounted ring runners. The ring runners rotate at high speeds on the upper surface of the spinning rings, the so-called ring crown, driven by a thread held by the ring runner. This results in high loads on the contact surfaces between the ring runner and the ring crown of the spinning rings. A bridge adjoining the ring crown is provided for securing the spinning rings in a machine; this bridge can terminate in a foot flange.The ring crown, as well as the base flange (or, if there is no base flange, the bridge), are manufactured in a wide variety of designs, each adapted in shape and geometry to the requirements of the respective machine and the intended design for mounting the spinning ring. The spinning ring is held in the machine within a so-called ring frame.

[0002] During operation, the contact surfaces between the spinning ring and the rotor heat up due to friction, and consequently, so does the yarn. The rapid rotation of the rotor on the spinning ring can generate local temperatures exceeding 400°C, which limits the operational capabilities of the rotor system. Due to these mechanical constraints, rotor speeds of more than 30,000 revolutions per minute cannot be exceeded with today's typical ring diameters without risking damage to the rotor or yarn. Through ongoing development of the spinning ring and rotor designs, this speed has been continuously increased, and today a maximum safe spinning speed for cotton is approximately 42 m / s and for polyester approximately 32 m / s. Developments in materials have primarily affected the surface finishes of the spinning ring and rotor, rather than the base material itself.The development of base materials for the spinning ring and rotor has received little attention since the invention of the ring spinning machine in the 19th century. Hardened carbon steel remains the standard material for both components. Numerous coatings have been developed for the spinning ring and rotor, significantly increasing their service life. However, these coatings have not resulted in a substantial increase in rotor speed. Special coatings, at least in the contact areas, have improved the sliding properties, extending the service life but barely increasing the rotor speed.

[0003] Various coating designs for spinning rings or ring rotors are known from the prior art. For example, EP 1 066 419 A1 discloses a phosphate-coated rotor, which reduces wear on the ring rotor. EP 3 052 684 A1 discloses a spinning ring with a chromium coating containing boron nitride, which also reduces wear on the ring rotor. US 200020162315 A1 discloses a nitrided rotor. Nitriding provides higher wear resistance and improved sliding properties. US 4677817 A discloses a ceramic-coated ring rotor to reduce wear and extend service life. Furthermore, US 2,970,425 discloses a nickel-coated spinning ring, which provides a uniform surface and thus reduces the coefficient of friction.

[0004] Further spinning rings are known from the publications JP S62 199822 A, DE 811 092 C and CN 107 021 752 A.

[0005] Reducing the wear of one component, as demonstrated in the prior art, is relatively easy to achieve; the component (e.g., the spinning ring) must be coated with the hardest possible layer or manufactured from an extremely hard material. The disadvantage of this is that the other component (e.g., the ring rotor) then wears out even faster. This is exacerbated by the temperature of the friction point, or rather the contact surfaces, which is higher in the ring rotor than in the spinning ring, thus accelerating the wear of the ring rotor despite the hardest coatings.

[0006] The object of the invention is therefore to create a spinning ring which enables a longer service life at today's speeds of the ring runner and an increase in the achievable upper limit of the speed of the ring runner.

[0007] The invention also aims to create a ring runner system that allows the speed limit of the ring runner to be increased to over 50 m / s (cotton).

[0008] The problem is solved by a spinning ring and a ring-runner system with the features of the claims.

[0009] To solve the problem, a spinning ring for a ring spinning or ring twisting machine is proposed, comprising a bridge and a ring crown. The ring crown is at least partially made of a tungsten sintered material with a tungsten content of at least 90%. By partially forming the ring crown with a tungsten surface, a number of advantageous properties are achieved compared to surfaces known from the prior art, such as those made of steel, chromium, chromium carbide, nickel-phosphorus, and others. The tungsten grains forming the sintered material have a hardness of approximately 450 HV. This prevents abrasive wear on harder ring runners, yet the hardness is high enough to withstand even abrasive wear. Currently used spinning ring surfaces reach hardnesses of up to 1000 HV, which leads to high wear of ring runners.Furthermore, the tungsten grains have a high thermal conductivity of approximately 180 W / mK, which is almost double that of conventional materials and coatings. This increased thermal conductivity leads to improved heat dissipation and thus to enhanced cooling of the spinning ring surface. The tungsten grains also have a melting point of approximately 3400°C, in contrast to the melting point of conventional materials at around 1900°C. This high melting point reduces the tendency for micro-welding, thereby delaying the destruction of the sliding surface.

[0010] When tungsten sintered material is subjected to dry friction, tungsten oxide forms, which is powdery, soft, easily meltable, and exhibits weak adhesion to the base material. This results in a self-lubricating effect that improves the sliding properties. In contrast, conventional coated spinning rings do not exhibit a self-lubricating effect during dry rubbing because, for example, in chrome-coated spinning rings, the chromium oxide that forms is solid and hard, creating a strongly adhering, continuous coating on the chrome surface.

[0011] Under these conditions, the use of spinning rings made of tungsten sintered material has a positive effect on the wear of all known ring rotors. The improvement achieved varies depending on the ring rotor surface. The smallest improvement is observed when using nickel-plated ring rotors. With uncoated carbon steel ring rotors, nitrided ring rotors, and CVD-coated ring rotors (CrC, TiC coatings), a speed increase of over 10-15% was achieved in addition to improved wear behavior.

[0012] Preferably, the entire ring crown is made of a tungsten sintered material with at least 90% tungsten. Manufacturing the entire ring crown, rather than a limited insert within it, simplifies the production of the spinning ring.

[0013] In an alternative embodiment, the spinning ring is provided with a foot flange on the side of the bridge opposite the ring crown. Various spinning ring designs exist, including those with two ring crowns. The design of the spinning rings with a bridge or with a bridge and foot flange depends on the method of mounting the spinning rings in the spinning or spinning-twisting machine.

[0014] The preferred tungsten sintering material is W97Ni2Fe. In principle, all available W-NiFe sintering alloys can be used. However, it has been shown that the best results are achieved when using the material W97Ni2Fe1 with a density of 18.5 g / cm³.

[0015] Furthermore, it is advantageous if the base flange and / or the bridge are made of copper or a copper alloy. When used as spinning rings, copper or copper alloys offer high thermal conductivity and, due to dynamic operation, good flexibility with corresponding dimensional stability. This also means that the part of the spinning ring made from the tungsten sintered material can preferably be attached to the ring crown or the bridge by a soldering process.

[0016] For certain applications, it can be advantageous if the base flange and / or the bridge are made of an aluminum bronze, preferably a nickel-aluminum bronze (CuAl10Ni5Fe4). A spinning ring corresponding to such an embodiment of the invention can be manufactured particularly cost-effectively and is characterized at the same time by high corrosion resistance and mechanical strength combined with sufficiently high thermal conductivity. Likewise, such a material pairing increases the visual detectability of a ring runner on a spinning ring, which generally applies to embodiments of spinning rings according to the invention with a base flange and / or the bridge made of copper or a copper alloy. Such increased visual detectability simplifies the inspection and, if necessary, also the replacement of ring runners.

[0017] For certain applications, it can be advantageous for the base flange and / or the web to be made of steel. Spinning rings with good thermal conductivity can be achieved if the base flange and / or the web is made of a carbon steel, in particular 100Cr6. Likewise, the use of a ferritic stainless steel (1.2083) or a duplex stainless steel (1.4462) for the base flange and / or the web of certain embodiments of a spinning ring according to the invention is advantageous.

[0018] Preferably, the entire spinning ring is made of a tungsten sintered material with at least 90% tungsten. This eliminates the need to manufacture a spinning ring consisting of several parts and join them together, for example, by brazing. When the entire spinning ring is made of a tungsten sintered material, there are no fundamental differences between conventional steel spinning rings and spinning rings made of tungsten sintered alloys, as both are turned from blanks or machined using subtractive processes. Even in the case of a spinning ring composed of several parts, the finished spinning ring is produced from a previously brazed tubular blank. However, unlike steel spinning rings, tungsten spinning rings are ready for use immediately after turning; the usual subsequent manufacturing processes, such as hardening, honing, polishing, and chrome plating, are unnecessary.

[0019] Furthermore, a ring-runner system for a ring spinning or ring twisting machine is proposed, comprising a spinning ring as described above and a ring runner made of high-speed steel (HSS) wire, the ring runner having a minimum hardness of 60 HRC. To achieve a maximum increase in the speed of the ring runner, the wear of the ring runner must be reduced without causing increased wear of the spinning ring, or vice versa. This means that the contact surfaces of the spinning ring and the ring crown, and thus both rubbing surfaces, must be considered and optimized as a pair. This optimization includes not only adjusting the surface hardness of the components but also other aspects, such as improving heat dissipation from the friction point or addressing chemical processes that may occur during friction (e.g., oxidation).An increase in the rotational speed, or velocity, of the ring rotor, achieved through optimization, leads to a corresponding increase in the production of the spinning machine.

[0020] HSS ring rotors can be manufactured from all known high-speed steels available in wire form. Ring rotor manufacturing is analogous to conventional ring rotor manufacturing from carbon steel, with the difference that the annealing, hardening, and tempering processes are carried out under different conditions. Known, material-specific hardness parameters must be applied for each HSS material. The achieved base hardness values, depending on the high-speed steel used, range from 850 to 1000 HV. HSS ring rotors generally do not require a coating and are ready for use after grinding and polishing.

[0021] The advantages of high-speed steel (HSS) rotors over carbon steel rotors stem primarily from their significantly higher hot hardness. Hardened carbon steels soften quite rapidly above approximately 300°C, whereas hardened high-speed steels retain their original high hardness up to about 550°C. During spinning operations, temperatures exceeding 300°C are common at the ring rotor friction surfaces; therefore, HSS steels expand the application possibilities for ring rotors to higher speeds. Even in the temperature range below 300°C, HSS steels offer significantly higher hardness and strength than carbon steels. Because high-speed steels are less brittle than carbon steels at maximum hardness, HSS ring rotors can be harder than conventional ring rotors, even at room temperature, exceeding 200 HV.A ring runner made of carbon steel must not be harder than 700 HV, otherwise it will break when placed on the spinning ring; in contrast, HSS ring runners only break when placed on the spinning ring from a hardness of about 950 HV.

[0022] Just as tungsten spinning rings outperform conventional spinning rings, HSS ring rotors are superior to virtually all common carbon steel ring rotors when used in combination with all types of spinning rings. However, here too, the maximum effect was only achieved with the tungsten ring. The following application examples demonstrate the speed increase achieved in specific cases.

[0023] Preferably, the high-speed steel corresponds to material 1.3343 according to DIN EN ISO 4957 (2018-11) with the material name HS6·5-2C. The use of this material has proven to be particularly advantageous.

[0024] In a combination of spinning rings made of tungsten sintered material with ring runners made of high-speed steels (HSS ring runners), an increase in the speed of the ring runner of over 20% could be achieved.

[0025] The following application examples demonstrate the speed increases achievable in individual cases when combining spinning rings with ring crowns made at least partially of tungsten sintered material (tungsten spinning rings) with common ring rotors. The listed designations are taken from the applicant's product catalog and correspond to commercially available ring rotors. Before the start of the test series, all spinning rings with the corresponding ring rotors were run in at a low speed (23-34 m / s) for several hours. A test series consisted of several identical trials, with each subsequent trial within a series being conducted at a slightly higher speed (ring rotor rotational speed). The running time of a trial per speed and ring rotor was one hour (a new ring rotor was used for each trial).All ring runners were weighed before and after the test to determine the degree of wear (measurement accuracy approx. 0.01 mg). During the test series, the speed was increased incrementally in 0.6 m / s steps. A specific ring runner wear threshold of 0.2 mg was defined as a reference point for comparison; ring runners with wear greater than 0.2 mg were considered worn. The maximum possible speed limit was set at the ring runner speed at which the first ring runners in the series wore out in a 60-minute test. No measurable wear of the spinning rings was observed in any of the tests. All application examples refer to laboratory tests with a 16-spindle spinning machine from SER.MA.TES. In all tests, the new components (tungsten spinning rings and / or HSS ring runners) were tested simultaneously with geometrically identical reference components from the prior art.This allowed for a direct comparison between old and new components under identical conditions. The combined tungsten spinning rings consisted of a ring crown made of the sintered material W97Ni2Fe1, which was soldered to a copper bridge. The HSS ring rotors were made of high-speed steel 1.3343 (M2). The maximum achievable ring rotor speed corresponds to the speed at which the same wear occurs on the ring rotor within the same operating time as at the reference ring rotor speed on the spinning ring-ring rotor pair being compared.

[0026] Example 1. A tungsten spinning ring was compared with a chrome-plated steel spinning ring in an application with uncoated carbon steel ring runners. Spinning ring type: T-flange rings Ø47x38, ring runner type: C1ELMudrISO35.5mg. Spinning parameters: Cotton, Ne 30, twist = 1000, non-compact. Reference ring runner speed with steel spinning ring: 20,000 rpm (39.8 m / s). Maximum ring runner speed with tungsten spinning ring: 23,300 rpm (46.3 m / s). This results in a speed and thus production increase of 16.3%.

[0027] Example 2. A tungsten spinning ring was compared with a chrome-plated steel spinning ring in an application with nitrided carbon steel ring runners. Spinning ring type: T-flange rings Ø47x38, ring runner type: C1SELudrISO31.5mg, spinning parameters: cotton, Ne 30, twist = 922, compact. Reference ring runner speed with steel spinning ring: 22,000 rpm (43.8 m / s), maximum ring runner speed with tungsten spinning ring: 25,300 rpm (50.3 m / s). This results in a speed and thus production increase of 14.9%.

[0028] Example 3. The use of a tungsten spinning ring with an HSS ring runner was compared with the use of a chrome-plated steel spinning ring with an uncoated carbon steel ring runner. Spinning ring type: T-flange rings Ø47x38, ring runner type: C1ELudrISO18.0mg, spinning parameters: cotton Ne 46, twist = 1000, non-compact. Reference ring runner speed with steel spinning ring: 22,000 rpm (43.8 m / s), maximum ring runner speed with HSS ring runner on tungsten spinning ring: 27,000 rpm (53.7 m / s). This results in a speed and thus production increase of 22.6%.

[0029] Example 4. The use of a tungsten spinning ring with an HSS ring runner was compared with the use of a chrome-plated steel spinning ring with an uncoated carbon steel ring runner. Spinning ring type: T-flange rings Ø47x38, ring runner type: C1MMudrISO63.0mg, spinning parameters: cotton Ne20, twist = 705, non-compact. Reference ring runner speed: 14,300 rpm (28.4 m / s), maximum ring runner speed with HSS ring runner on tungsten spinning ring: 17,300 rpm (34.4 m / s). This results in a speed and thus production increase of 21.1%.

[0030] The invention is explained below using an exemplary embodiment and illustrated in more detail with drawings. These show... Figure 1: A schematic representation of a spinning station of a ring spinning machine; Figure 2: A schematic representation of a spinning ring with ring runner; Figure 3: An enlarged representation according to Figure 2 and Figure 4 a schematic representation of a second and third embodiment of a spinning ring.

[0031] Figure 1Figure 1 shows a schematic representation of a spinning station in a ring spinning machine, where modern ring spinning machines have up to 2,000 or more such spinning stations. In the ring spinning machine, a fiber bundle, a so-called wick 1, is fed to a drafting unit 2. The wick 1 is drawn by the drafting unit 2 into a thread 3. The drafting unit 2 shown is a so-called belt drafting unit, which is typically used for cotton. Various designs of drafting units 2 are known from the prior art, depending on the application. After the drafting unit 2, the thread 3 is guided via a thread guide 4 to a ring runner 10. After passing the ring runner 10, the thread 3 is wound onto the yarn bobbin 5. The yarn bobbin 5 is set in rotation 6 by a drive 7. This rotation 6 of the yarn spool 5 carries the ring runner 10 along with the thread 3, which causes the thread 3 to be given a twist and thus the yarn is formed.Because the ring runner 10 is held on the spinning ring 8, it is forced to rotate around the yarn bobbin 5. The spinning ring 8 is held stationary on a ring frame 9.

[0032] Figure 2Figure 1 shows a schematic representation of a spinning ring 8 with an attached ring runner 10. The spinning ring 8 shown as an example consists of a ring crown 14 and a bridge 15 adjoining the ring crown 14. The bridge 15 serves to secure the spinning ring 8 in a spinning machine. The ring runner 10 is placed on the ring crown 14 and partially encloses it. The ring runner 10 is designed such that it encompasses the ring crown 14 sufficiently to prevent the ring runner 10 from falling off the ring crown 14, while still allowing the greatest possible freedom of movement for the ring runner 10 relative to the ring crown 14. Numerous shapes and designs of ring crowns 14 and ring runners 10 are known from the prior art. The rotational movement transmitted by the thread 3 to the ring runner 10 causes the ring runner 10 to rotate around the spinning ring 8 in the direction of the runner rotation 11.This rotation in turn creates a centrifugal force 12 acting on the ring runner 10. This pushes the ring runner 10 against the inside of the spinning ring 8, or the ring crown 14.

[0033] In Figure 3 This situation is shown enlarged. The ring runner 10 slides along the spinning ring 8, creating a contact surface 13. At least in the area of ​​this contact surface 13, it is essential that the ring runner 10 exhibits good sliding properties relative to the spinning ring 8. By selecting an appropriate material for the ring crown 14, at least in the area of ​​the contact surface 13, the sliding pair between the spinning ring 8 and the ring runner 10 is improved. The ring crown 14 is shown with an insert 16 made of a tungsten sintered material with at least 90% tungsten in the area of ​​the contact surface 13. The insert is connected to the ring crown by a soldering process on a base material, for example, copper.

[0034] Figure 4Figure 1 shows a schematic representation of a second and third embodiment of a spinning ring 8 according to the invention. The illustration is divided into two parts, with both the left and right embodiments showing a spinning ring 8 with a ring crown 14, a bridge 15, and a base flange 17 arranged on one side of the bridge 15 facing away from the ring crown 14. The base flange 17 serves to fasten the spinning ring 8 in a spinning machine. In the right embodiment, the ring crown 14 is made of a tungsten sintered material with at least 90% tungsten, and the remaining part of the spinning ring 8, namely the bridge 15 and the base flange 17, are made of a standard material, for example, copper, a copper alloy, steel, or a light metal. The ring crown 14 is connected to the bridge 15 by a soldering or welding process. In contrast, in the left-hand version, the entire spinning ring 8 is made of a tungsten sintered material with at least 90% tungsten.The present invention is not limited to the embodiments shown and described. Modifications within the scope of the claims are also possible. Legend

[0035] 1 Fuse 2 Drafting unit 3 Thread 4 Thread guide 5 Yarn bobbin 6 Rotation 7 Drive 8 Spinning ring 9 Ring bank 10 Ring runner 11 Runner rotation 12 Centrifugal force 13 Contact surface 14 Ring crown 15 Bridge 16 Insert 17 Foot flange

Claims

1. A spinning ring (8) for a ring-spinning or ring-twisting machine, having a web (15) and a ring crown (14), characterized in that the ring crown (14) consists at least partially of a tungsten sintered material having at least 90% tungsten.

2. The spinning ring (8) according to claim 1, characterized in that the entire ring crown (14) consists of a tungsten sintered material having at least 90% tungsten.

3. The spinning ring (8) according to at least one of the claims 1 to 2, characterized in that the spinning ring (8) is provided with a foot flange (17) on a side of the web (15) opposite the ring crown (14).

4. The spinning ring (8) according to at least one of the claims 1 to 3, characterized in that the tungsten sintered material is W97Ni2Fe1.

5. The spinning ring (8) according to at least one of the claims 1 to 4, characterized in that the foot flange (17) and / or the web (15) is made of copper or a copper alloy.

6. The spinning ring (8) according to claim 5, characterized in that the copper alloy is an aluminum bronze, preferably CuAl10NiSFe4 nickel aluminum bronze.

7. The spinning ring (8) according to at least one of the claims 1 to 4, characterized in that the foot flange (17) and / or the web (15) is made of steel.

8. The spinning ring (8) according to at least one of the claims 1 to 7, characterized in that the part of the spinning ring (8) produced from the tungsten sintered material is applied to the ring crown (14) or to the web (15) by a soldering process.

9. The spinning ring (8) according to at least one of the claims 1 to 7, characterized in that the spinning ring (8) as a whole consists of a tungsten sintered material having at least 90% tungsten.

10. A ring / traveler system, characterized in that a spinning ring (8) according to any of claims 1 to 9 and a ring traveler (10) made of a wire made of high-speed steel (HSS) are provided, wherein the ring traveler (10) has a minimum hardness of 60 HRC.

11. The ring / traveler system according to claim 10, characterized in that the high-speed steel corresponds to the material 1.3343 according to DIN EN ISO 4957 (2018 / 11) with the material name HS6·5-2C.

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